Current-Perpendicular-to-Plane Giant Magnetoresistance Effect in van der Waals Heterostructures

Abstract

Spin-dependent transport in full van der Waals (vdW) giant magnetoresistance (GMR) junctions with the structure of ${\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}/X{\mathrm{Te}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$ (X = $\mathrm{Pt}$, $\mathrm{Pd}$) is investigated by using first-principles calculations. The ballistic conductance, magnetoresistance (MR), and resistance-area product (RA) are calculated in a current-perpendicular-to-plane (CPP) geometry. A giant magnetoresistance of around 2000% and RA less than 0.3 \ensuremath{\Omega} \textmu{}${\mathrm{m}}^{2}$ are found in the proposed vdW CPP GMR. In addition, the spin-orbit-coupling effect on transport and anisotropy magnetoresistance (AMR) are also investigated. The calculated AMR is found to be around 20% in the ${\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}/$trilayer ${\mathrm{Pd}\mathrm{Te}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$ CPP GMR. Both GMR and AMR in the proposed vdW CPP GMR mainly originate from the bulk electronic structure properties of ${\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$. This work demonstrates a vdW CPP GMR with superior advantages, including perpendicular magnetic anisotropy, large GMR, low RA, and sizable AMR, which may stimulate future experimental explorations and should be appealing for its application in spintronic devices, including magnetic sensors and memory.